1 / 13

Mental Images

Explore how mental images are encoded in the visual system and utilized in cognitive processes like problem-solving, mental rotation, concepts, and categories. Understand the role of top-down processing, scanning mental images, and the basic level of categorization.

mstone
Download Presentation

Mental Images

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Mental Images • The visual system encodes patterns of light and their inter-relationships • Images in the visual system are partly created by these patterns of light on the retina. • However, the image on the retina, is two-dimensional, upside down, and mostly out of focus. HKU

  2. Top-Down Processing in the Visual System • The three-dimensional, right-side up, clear image that we see is created by our brain. • Is it possible that cognitive processes such as problem-solving can use this access to the visual system even when there isn’t stimulation on the retina? HKU

  3. Scanning Mental Images • Kosslyn, Ball, and Reiser (1978) had subjects memorize picture of island. • Asked them to focus on one location of their mental image, and then asked them to (mentally) go to another location on the image. • The time to get to the new location was proportional to the distance on the actual picture. HKU

  4. Mental Rotation • The time required to mentally rotate objects in space (in order to recognize them) is linearly related to how much they need to be rotated to be in a familiar position Shepard, 1968 Cooper, 1975 HKU

  5. Concepts and Categories • Is the world naturally divided into categories or are the categories we perceive a consequence of how our minds see the world? (Philosophy) • Theories of concepts have changed significantly over the past 30 years. HKU

  6. From Definitions to Theories • For centuries, concepts were seen as sets of necessary and sufficient features that define categories. • Rosch (1975) changed this view by presenting evidence that concepts are more probabilistic. HKU

  7. Prototypes and Family Resemblance • Concepts are collections of features that are neither necessary nor sufficient. • When we learn category concepts, we compare sets of features: if most features are similar and few are dissimilar, then we group thing together --> family resemblance HKU

  8. Concepts as collections of prototypical features • From observing numerous examples of particular categories, we form prototypes --> non-existent category representatives that embody all of the most common features. HKU

  9. The Basic Level • Prototypes and family resemblance are strongest at what Rosch termed the basic level --> bird vegetable game car HKU

  10. Empirical Evidence for the Basic Level • Subjects are asked to rate properties of different instances of categories (e.g., how important is having two legs to being a bird?) • These ratings are then used to compute family resemblance scores for different types of birds. • Subjects typicality ratings are correlated with FR scores. HKU

  11. Summary • The basic-level cuts the world up into categories that have the most family resemblance. e.g., furniture mammal chair dog car seat poodle HKU

  12. Picking Out the Right Features • Why don’t we compare objects in terms of volume, time in a specific location, distance from home, etc. --> infinite number of features • How do we choose the right ones? HKU

  13. Concepts as Theories • Concepts are more than just collections of probabilistically inter-related features. • They are held together by a theoretical /explanatory glue. HKU

More Related